Tachycardia, anyone experience this at odd times with no warning? Help me?

You need to see a cardiologist and possibly get a stress test that will tell whether you may have diminished blood flow to your heart muscle. A cardiologist will be able to determine if you have some blockage in your coronary arteries that supply the heart muscle. No, don't wait to die but instead see a good cardiologist and get the tests to determine as what is going on.